IR Ink writing pens: Our IR ink writing pens writes in a nearly invisible ink which will fluoresce in the infrared spectrum. Using a 630nm red filter, you can see the IR1 ink. We have two types of infrared inks: IR1 peak excitation is at 793nm and peak emission at 840nm while our IR2 ink has a peak excitation at 824nm and peak emission at 885nm.

IRDC2: Visible to infrared fluorescing powder. When stimulated with a blue or red light, the powder will fluoresce in the infrared range.

IRUCG, IRUCR, IRUCB: Infrared to visible fluorescing powder. When stimulated with infrared light, the powder will fluoresce in the visible range.

Up / Down Conversion refers to the fluorescence shift up or down the spectrum from the excitation source. All fluorescence occurs when a material is stimulated with energy (usually light) at one frequency (say a black light) and the material remits some of the energy at a lower frequency (your typical fluorescent paints the glow in the human visible range).

Fluorescence can occur at any point of the electromagnetic spectrum. Different materials exhibit different fluorescent properties. A material might absorb ultraviolet light and emit visible light, or absorb visible and emit infrared, or absorb near infrared and emit far infrared.

Fluorescence almost always occurs as a shift down in photon energy levels or down-conversion. An ultraviolet light photon has higher energy than a visible light photon which has higher energy than an infrared photon.

In the ultraviolet to infrared spectrum, energy levels go from

UVC - ultraviolet short wave - 250nm (highest energy level)

UVB - ultraviolet medium wave - 300nm

UVA - ultraviolet long wave - 370nm

Visible light - blue (400nm) to red (700nm)

Infrared - 700nm to 8000nm (lowest energy level)

Within this spectrum, UVC has the highest energy or shortest wavelength. Infrared has the lowest energy or longest wavelength.

Up-Conversion is a very unusual phenomenon. A counter-intuitive anti-stokes process occurs where the material absorbs lower energy photons and emits higher energy photons as fluorescence. The trick is that up-conversion materials absorb two or more low energy photons and then emit one high energy photon. By definition, up-conversion phosphors must be much less efficient than down-conversion phosphors. Typically, up-conversion phosphors are illuminated with high intensity light sources such as lasers in a controlled (subdued) lighting environment.

We also have a large library of fluorescent materials not listed on our site. Contact us if you have a particular need.

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